Process for obtaining silk fibroin.



UNITED STATES PATENT OFFICE.

CARL RUDOLF BAUMANN, OF GAVIRATE, ITALY, AND GOT'ILIEB GOTTFRIEDDIESSER,

OF ZURICH, SWITZERLAND.

PROCESS FOR OBTAINING SILK FIBROIN.

eraaw. No Drawing.

To all whom it may concern:

Be it known that we, CARL Rooonr BAU- MANN, silk manufacturer, a subjectof the Swiss Confederation, residing at Gavirate, in the Kingdom ofItaly, and Gorrmnn Go'rrrnnn) Dmssnn, scientific chemist, a subject ofthe German Emperor, residing at Zurich,

Switzerland, have invented new and useful Improvements in Processes forObtaining Silk Fibroin, of which improvements detailed account follows.

Besides the methods used by the silk-dyers for scouring the silk,several solvents, acid or alkaline, were hitherto known for theproduction of silk-fibroin. Some, or even all, of these agents however,effect a more or less fargoing decomposition of the fibroin and thusproduce results which have, as it would seem, prevented, to this day,solutions of silk-fibroin from being practically made use of fortechnical purposes.

The present invention is the result of elaborate experiments with agreat variety of solvents, experiments by which it was proved beyonddoubt that an excellent method for the production of silk-fibroin, at

ordinary temperatures, consisted in using in the presence of heat.

When the glands are dissolved in formic acid, the serecin remains anundissolved tube. The formic acid solution having been evaporated, avery lustrous thin skin of a somewhat lesser elasticity than that of theSpecification of Letters Patent.

Application filed November 27, 1908.

Patented Nov. 29, 1910.

Serial No. 464,646.

fibroin of raw silk as obtained from the scouring trough, but having allthe other qualities of the last named fibroin, has resulted. In orderthen to impart the degree of elasticity still wanting, a preliminaryaddition is made to the formic solution, of an appropriate substance,for instance, glue,

fish-glue, starch, casein, dextrin, shellac,-

.the swelling of the fibroin caused by its treatment with formic acid.can be utilized for manufacturlng, out of s1lk and waste s1lk,insulatlng bodies, as bands, ribbons,

sticks, plates etc., in order to utilize the reat insulating power ofsilk. Again, finished silken fabrics can be rendered airand waterproofby being treated with formic acid.

Claims: 1. The-process of obtaining silk-fibroin, which consists indissolving the spinning glands of silkworms with formic acid, as setforth.

2. The process of obtaining silk fibroin which consists in dissolvingthe spinning glands of silk Worms with formic acid by the aid of heat.

. CARL RUDOLF BAUMANN.

GOTTLIEB GOTTFRIED DIESSER.

Witnesses LEVAILVLANT, J os. SIMON.

